Spray gun



April 30, 1968 B. E. ENSSLE 3,380,705

SPRAY GUN Filed June 28, 1965 United States Patent O 3,380,705 SPRAY GUNBruno E. Enssle, Boulder, Colo., assignor to Binks ManufacturingCompany, Chicago, Ill., a corporation of Delaware Filed June 28, 1965,Ser. No. 467,635 12 Claims. (Cl. 251-89) ABSTRACT F THE DISCLOSURE Anairless paint spray gun characterized by safety features mitigatingmisuse of the gun and injury to human beings; specifically, a controlknob for disconnecting the gun trigger from the uid control valve forpreventing inadvertent opening of the valve during cleaning, replacementof nozzles and Ithe like, and a valve and valve seat arrangement suchthat a solid jet of fluid cannot issue from the gun when the nozzle isnot in place. A further characterizing feature resides in a readilyreplaceable valve and sealing gland cartridge for airless spray gunsfacilitating cleaning and repair of the gun; said cartridge including aflexible link in the valve actuating means facilitating broadmanufacturing tolerances.

The present invention relates to apparatus for spray painting, andparticularly, to an improved airless spray painting gun. The object ofthe invention is to provide improvements in spray painting gunsfacilitating manufacture, assembly and repair of such guns.

It is in particular an object of this invention to provide an airlessspray gun incorporating the safety feature that the gun cannot beoperated during replacement, cleaning or inspection of the gun nozzle,whereby to avoid injury to the operator or bystanders consequent uponinadvertant or accidental operation of the gun. Specifically, in airlessspray painting, paint or other coating material is supplied to the gunat pressures of up to 3,000 pounds per square inch, and this paint orcoating material is hydraulically atomized by passage through a Verysmall orifice in the gun nozzle. The coating material issuing from thenozzle is at such high pressure and traveling at such high speed that itis capable of severing a finger or inflicting great bodily harm bypenetration of the coating material through the skin of the person whois inadvertantly or accidentally sprayed. Should the spray hit a vitalportion of the human body, it is quite likely that death might result.Accordingly, the incorporation of the safety feature of the presentinvention in an airless spray gun affords very substantial practicaladvantages.

Another object of the present invention is to provide a combined valveand sealing gland cartridge for spray guns characterized in that thecartridge is insertable in and removable from the gun body as a unit,whereby to facilitate manufacture and assembly, cleaning repair of thegun.

A further object is the provision of a valve and seal cartridge asaforesaid embodying fiexible valve stem means accommodating broaddimensional tolerances in manufacture of the gun; and also embodying aspring confined between the valve and `the sealing gland for bothbiasing the valve to its seat and maintaining the gland in sealingrelation to the gun body and the valve stem.

A still further object of the invention is the provision of an improvedvalve and valve seat for spray guns facilitating economical manufactureof the same from wear resistant materials, providing a quick-openingvalve port, mitigating pulsations in material delivery and splitting ofthe spray gun, and also affording certain safety factors in use of thegun.

3,380,705 Patented Apr. 30, 1958 ICC These and other objects andadvantages of the invenf tion will become apparent in the followingdetailed description.

Now, in order to acquaint those skilled in the art with the manner ofmaking and using the spray gun of the present invention, there shall bedescribed in connection with the accompanying drawings, a preferredembodiment of the spray gun and the preferred manners of making andusing the same.

In the drawings:

FIGURE 1 is a top view, partly in plan and partly in horizontal section,of a preferred embodiment of the spray gun of this invention;

FIGURE 2 is a vertical longitudinal section of the gun takensubstantially on line 2 2 of FIGURE 1;

FIGURE 3 is a rear elevation of the gun, the view being taken from theright of FIGURE 2 and showing the gun in safety position;

FIGURE 4 is a fragmentary longitudinal section of the gun takensubstantially on line 4-4 of FIGURE l; and

FIGURE 5 is a fragmentary enlargement of a part of FIGURE 2 showing thevalve and valve seat members.

Referring to the drawings, the airless spray gun of the presentinvention is shown as comprising a gun body 10 including a handle 12 anda head portion 14. The head portion 14 is provided with a longitudinalbore 16 extending therethrough, and the handle is provided with adiagonal bore 18 communicating with an intermediate portion of the bore16. A nipple 20 is threaded into the bore 18 at the lower end of thehandle for supply thereto of coating materials.

The forward end of the longitudinal bore 16 receives a threaded fitting22 which in turn threadably receives a valve seat retainer 24, thelatter removably mounting a valve seat 26 and a combined seat lockingstud and valve guide 28 in the front of the gun body. The fitting 22also threadably receives a cap 30 which detachably mounts an airlessspray nozzle 32 on the lgun body in alinement with the port in the valveseat 26, a seal 34 suitably being inserted between the nipple and theretainer 24.

Slidably inserted in the longitudinal bore 16 is a selfcontained valvecartridge 36 comprising a valve member formed of a ball valve 38 and anintegral needle portion 40, an integral rigid threaded stem portion 42,a fiexible stem link 44- adjustably connected to the portion 42, apacking gland assembly 46 slidably receiving the stem link 44, a stemextension 48 having a one-way connection with the rearward end of thelink, a retainer 50 for the gland assembly 46 and the extension 48, anda compression spring 52 encircling the stem between the portion 42 andthe gland assembly 46.

The link 44 is comprised of a length of flexible wire provi-ded with ahead at each end thereof. The head at the forward end of the wire isslidably received in a collar 54 which is threaded on the stem portion42 to facilitate adjustment between the two, the collar when adjustedbeing secured to the portion 42 by a lock nut 56. The head at therearward end of the flexible wire is slidably received in the extension48, and the extension has only a rearwardly facing seat for the headwhereby the extension can operate only to pull the wire rearwardly. Theiiexible wire particularly accommodates mis-alinement of the valve 38440and the packing gland, extension and retainer 46-48-50 withoutintroducing lost motion in the interconnection of the valve and theextension, whereby to alleviate the degree of precision required inmachining the body 10, i.e., the retainer 50 and the valve seat 26 maybe mis-alined without disadvantageous consequences.

The flexibility afforded by the link 44 also contributes to attainment'of exceptionally effective results of an improved needle valve andvalve seat structure provided in accordance with this invention, whichstructure per se affords substantial advantages in the art.Specifically, the invention provides a ball type needle valve and valveseat wherein both the ball and the seat may be fabricated of extremelywear resistant materials, notably tungsten carbide, and yet afford aneffective seal therebetween; whereas it has heretofore been necessary inball type needles -to form one of the members of tungsten carbide andthe other of a softer material, or in the alternative to adopt aconventional needle valve rather than a ball valve.

As shown in FIGURE 2, the ball 38 is a sphere welded or otherwisesecured to the stern 40, and the valve seat 26 is a unitary memberhaving a conical recess in the rear face 4thereof forming the valveseat. Consequently, with the supplemental aid of the freedom of movementafforded by the link 44, the ball 38 is funneled or cammed by theconical seat 26 into a perfectly seated engagement with the seat along acontinuous circular line of seating contact. In the preferredembodiment, the conical bore forming the ball seat is extendedcontinuously through the seat member 26 to form a valve port onlyslightly smaller than the diameter of `the ball, whereby the ball 38sits within the port substantially flush with or projecting forwardly ofthe front face of the member 26. This disposes the valve as close aspossible to the spray nozzle 32V and results in mitigation of spittingand spray pattern deficiencies at the time when the valve is opened andclosed and the supply of material to the nozzle is initiated anddiscontinued. Also in the preferred embodiment, the conical valve seathas a fairly wide flare (eg` 60 or more degrees) so that the ball isoperative to fully open and to close the port quickly to mitigatespitting and spray pattern deficiencies. Moreover, the ball in its openposition deflects the material passing through the port in such manneras to form a spray (not a solid jet of material) when the nozzle 32 isremoved, whereby to afford a further safety factor for the operator wheninspecting or replacing the nozzle.

To mount the valve stem retainer 50, the bore 16 is formed with aradially inwardly directed shoulder at a location rearwardly of thepoint of intersection therewith of the diagonal bore 18, and theretainer is provided with a flange engaging said shoulder. The retainerin turn defines a first forwardly facing seat for the gland assembly 46.The gland assembly comprises a rearwardly disposed gland backing 58engaging the seat therefor in the retainer, a generally conical piece ofcompressible packing gland material 60, a gland seat 62 having arearwardly facing conical recess receiving the piece 60 of glandmaterial, and a spring mount 64 forwardly of the gland seat. In use,`the spring 52 urges the valve 38-46 forwardly against its seat 26 andurges the gland assembly rearwardly to seat the backing 58 in theretainer 50 and to exert a compressive force on the conical surfaces ofthe gland material to cause the gland to be squeezed radially outwardlyand inwardly into sealed engagement with the retainer 50 and theflexible link 44.

Rearwardly of the gland seat, the retainer 50 is formed to define asafety stop or shoulder for the stem extension 48, the extension havinga radial flange at its forward edge normally spaced forwardly of thestop or shoulder. In use, the stop and flange positively preventexcessive rearward movement of the extension 48 and thus preventexcessive pulling stress on the valve stem. In addition, the particularadvantage is afforded that should the iiexible link break or becomedisassociated from the head at the forward end thereof, the extension 48cannot be pulled (or pushed by fiuid pressure) so far rearwardly as todisassociate the link from the sealing gland 60, thereby to preventleakage from the gun even if the valve stem is broken.

In the preferred embodiment of the gun, a cylindrical paint `strainer 66is extended between the retainers 24 4 and 50 to cause the paint to bestrained in its passage from the supply duct 18 to the spray nozzle 32.

The retainer 50 and the valve stem extension 48 extend rearwardly of theexterior of the gun body and define mounting surfaces rearwardly of thebody for a manually manipulatable safety knob 68. The knob lhas aforward cylindrical bore conformably receiving and rotatably mountingthe knob on the retainer 50, an intermediate bore 69 of non-circularcross-section engaging a non-circular portion of the extension 48 andconnecting the two together for conjoint rotation, and a rearwardly opencylindrical bore receiving a nut or threaded abutment 70 that isadjustably threaded on the stem extension 48. The abutment 70 is spacedslightly rearwardly of the opposed surfaces of the knob, but is adaptedfor engagement by the knob upon rearward movement of the latter to exerta rearward pull on the valve stern to open the valve. A set screw 72locks the abutment 70 in adjusted position on the extension 48, and aspring 74 forming part of a detent means is Confined between the knoband the abutment to urge the knob forwardly toward the gun body and tourge the abutment rearwardly to eliminate lost motion between theextension 48 and the exible stem link 44.

A valve actuating trigger is pivotally mounted on the head portion 14 ofthe gun body, the trigger including a nger grip portion 76 forwardly ofthe handle 12 and a pair of bifurcations 78 extending to opposite sidesof the head 14 and pivotally connected thereto by screws 80 or the like.Preferably, the head portion 14 is recessed at its opposite sides toreceive the bifurcations 78, whereby portions of the body rearwardly ofthe trigger are alined with the two bifurcations. Slidably mounted inthe latter portions of the gun body are a pair of actuator rods 82 whichextend forwardly into the recesses provided for the bifurcations andrearwardly to the rear face of the gun body, the rods or pins beingtrapped in operative position by C-rings 84 engaging the portionsthereof between the gun body and the trigger bifurcations. To eliminateor control Wear between the rods and the trigger, and to accommodateeconomical formation of the trigger, a wear plate 85 is provided betweeneach bifurcations 78 and the head of the adjacent rod 82. Each wearplate 85 preferably comprises a tab portion complementing the upper endof the trigger bifurcation and pivotally mounted on the respective screw80, and an outturned tab extending into a recess in the rearward face ofthe bifurcation at a point alined with the respective rod 82.

In the illustrated embodiment of the invention, as shown particularly inFIGURES 1 and 3, the rods 82 are disposed parallel to the valve stem atthe same elevation and equal distances to opposite sides of the stem.The knob 68 is of generally elliptical configuration in rear elevationand includes a pair of oppositely extending eccentric portions 86selectively rotatable into and out of alinement with the rods 82. Whenthe eccentric portions are alined with the rods, squeezing of thetrigger causes the rods to move the knob rearwardly, the knob in turnengaging the abutment 70 and thereby pulling rearwardly on the stemcomponents 48, 44 and 42 to open the valve 38-40. When the trigger isreleased, the spring 52 causes all of the components to return to theirnormal positions as illustrated in FIGURE 1 wherein the valve is closed.

Should it be desired to render the gun inoperative, for example when thegun is idle, and to afford in particular the safety feature that the guncannot be operated during replacement, cleaning or inspection of thenozzle, it is only necessary to rotate the knob 68 a fraction of a turnto move the eccentric portions 86 out of alinement with the rod 82. Inthis condition, the trigger and the rod cannot lmove the knob 68, andthe knob itself cannot be moved except by extreme purposeful efforts,whereby the valve cannot be opened accidentally or inadvertantly.Consequcntly, accidental or unpremeditated actuation of the trigger willnot result in opening the valve, and danger of injury to the operator orbystanders from the high pressure coating material emanating from thenozzle 32 is alleviated.

The knob 68 and actuator rods 82 are preferably provided with detentmeans for rereasably retaining the knob extension 86 in alinement withthe rods 82 and for deterring re-alinement of the same when in safetyposition, thereby to enhance the safety feature and render the same morepositive. To this end, detent balls 88 are secured in sockets thattherefor in the knob extensions 86 and the rearward ends of the rods 82are provided with conical recesses 90 for reception of the balls, thespring 74 normally retaining the knob and thus the balls 88 inengagement with the rearward surface of the gun body and the rearwardends of the rods. Also, the trigger is inclined forwardly from itspivots 80 whereby the pendulus weight of the trigger portion 76 exerts arearward biasing force on the rods to maintain the rods in engagementwith the detent balls. When the knob is rotated to safety position, thissame pendulum action of the trigger shifts rods 82 rearwardly of the gunbody, whereby the rods prevent rotation of the knob back to operativeposition. Only when the trigger is released and the gun is pointeddownwardly (which is a safe holding position for the gun) will thetrigger and the rods move forwardly to permit the knob to be rotatedback to operative position. Thus, operator safety is assured.

The gun construction above described, in addition to the advantagesalready noted, facilitates rapid assembly and disassembly of the gun forconvenience in manufacture and for convenience in the field when it isdesired to clean the gun or repair or replace parts thereof.Specifically, the knob 68 may be held against rotation, thereby to holdthe stem extension 4S against rotation so that the set screw 72 may beloosened and the abutment 70 removed from the stern extension. Then, byholding the body of the gun, the nozzle cap 39 may be unscrewed, and theretainer 24 may be removed from the forward end portion of the gun.Thereafter, the self-contained valve cartridge 36 and strainer 66 mayreadily be removed as a unit from the oun body simply by pulling on thevalve 38-40.

Thus, the objects and advantages of the invention have been shown hereinto be attained in a convenient, economical and practical manner.

While a preferred embodiment of the spray gun of the invention has beenillustrated and described herein, it is to be appreciated that variouschanges, rearrangements and modifications may be made in suchembodiment" without departing from the scope of the present invention,as defined by the appended claims.

What is claimed is:

1. In a spray gun or the like, a body, a valve seat in the body, a valvemovable to and from the seat to control fiuid flow, said valve having astem extending to the exterior of the body, la knob engaging said stemexteriorly of said body, and an actuator rod slidably mounted into thebody in spaced generally parallel relation to said stem, said knobincluding -a portion movable into and out of alinement with said -rod toaccommodate and prevent, respectively, actuation of said valve.

2.. In a spray gun or the like, a body, a valve seat in the body, avalve movable to and from the seat to control fluid ow, said -valvehaving a stem extending to the exterior of the body, a knob engagingsaid stem exteriorly of said body, and an actuator rod slidably mountedin t-he body in spaced generally parallel relation to said stem, saidknob including la portion movable into and out of alinement 4with said.rod to accommodate and prevent, respectively, actuation of said valve,said rod and said knob including detent means normally retaining saidportion of said knob in alinement with said rod and deterringrealinement of said portion with said rod when the two rare not inalinement.

3. In a spray gun or the like, a body, a valve seat in the body, a valvemovable to and from the seat to control fluid flow, said valve having astem extending to the exterior of the body, a knob engaging said stemexteriorly of said body, a trigger ypivoted on said body includingbifurcations to opposite sides of said stem, and a pair of rods slidablymounted in said body to opposite sides of and generally parallel to saidstem, said rods extending Ibetween a respective bifurcation of saidtrigger and said knob7 said kno-b including op positely extendingeccentric portions rotatable into and out of alinement with said rods toaccommodate and prevent, respectively, actuation of said valve by saidtrigger.

4. In a spray gun or the like, a body, a valve seat in the body, a valvemovable to and from the seat to control fluid flow, said valve having astem including a rigid portion adjacent the valve, a stem extensionremote from said valve and extending to the exterior of the -body 'and aexible intermediate portion, a spring between the body and said rigidportion normally biasing said valve towar-d said seat, a knob engagingsaid stem extension exteriorly of said body, and an actuator rodslidably mounted in lthe -body in spaced generally parallel relation tosaid stem and movable conjointly therewith to open and to accommodateclosing of the valve, said knob including a portion movable into and outof alinement with said trod to accommodate and prevent, respectively,opening of said valve.

5. In a spray gun or the like; a body having a forwardly open fluidpassage including a rearwardly spaced forwardly facing seat; a valveassembly slidably positioned in said passage, said assembly comprising a-forwardly disposed valve, a valve stem including :a flexible linkextending rearwardly from said valve, sealing gland means slidablyreceiving said .link and engaging against said forwardly facing seat,and means between said valve and said gland means for exerting acompressive force on said gland to cause the salme to seal in saidpassage and about said link and for biasing said valve forwardly; and -avalve seat removably inserted in the forward end of said passage forco-operation with said valve.

6. In a spray gun or the like; a body having a forwardly open fluidpassage including a rearwardly spaced forwardly facing seat; a valve,valve spring and packing gland assembly slidably positioned in saidpassage, said assembly comprising a forwardly disposed valve, a valvestern including a exible link a-djustably connected to said valve andextending rearwardly from said valve, a gland seat slidably receivingsaid link and having a rearwardly facing conical seat, -a conical glandslidably `receiving said link and engaging in said gland seat, -a glandbacking slidably receiving said link and engaging against said forwardlyfacing seat, and a compression spring encircling said link and extendingbetween said valve and said gland seat for exerting a compressive forceon said gland to cause the same to seal in said passage and about saidlink and for biasing said valve forwardly; la valve seat Iremovablyinserted in the forward end of said ypassage for co-operation with saidvalve; and means .rearwardly of said gland detachably connected to saidlink for pulling said valve away from said valve seat.

7. In a spray gun or t-he like, a valve cartridge comprising `a valve, avalve stem including a rigid portion extending rearwardly from saidvalve, -a flexible link, means -adjustably connecting said link to saidrigid portion, and an extension on the rearward end of said link,packing gland means slid-ably receiving said Ilink between saidconnecting -means and said extension, a retainer for said extension andsaid gland means including a forwardly facing seat for said gland means,and means between said valve and said gland means yieldablly urging saidvalve forwardly and said gland means rearwardly toward its seat.

8. A spray gun comprising a igun body having a fluid passage thereinincluding a bore extending longitudinal-ly through the body from thefront to the rear thereof, a valve seat removably mounted in the forwardend of said bore, a valve slidably positioned in said bore andengageable with said seat, a rearwardly extending stem on said valve,packing gland means seated in said bore and slidably .receiving saidstern, means between said valve and said gland yield-ably iurging saidvalve forwardly to its seat and said gland means rearwardly to its seatin said bore, an abutment member rearwardly of said body adj'ustablyconnected to said stem, a knob engaging said abutment member rearwardlyof said body, an actuator rod slidably mounted in said body in spacedgenerally parallel rela-tion to said stem and exten-ding to the rear ofsaid body, said knob including a portion movable into and out ofalinement with said rod to accommodate and prevent, respectively,movement of said knob vby said rod, and means for moving said rod.

9. A spray gun comprising a gun body having a duid passage thereinincluding a 'bore extending longitudinally through the body from thefront to the rear thereof; a valve seat removably mounted in the forwardend of said bore; a valve cartridge slidably positioned in said boreincluding a valve engageable with said seat, a rearwardly extendingvalve stem including a iiexible link adjustably connected to the saidvalve, a packing gland assembly slidably receiving said stem, a retainerseated in said bore adjacent the rear thereof and providing a forwardlyfacing seat for said gland, a spring encircling said stem between saidvalve and said gland assembly and urging said valve forwardly to itsseat and said gland assembly rearwardly to its seat, and a stemextension connected to said stem rearwardly of said gland assembly fortransmitting only rearward pulling force to said stem; an abutmentmember adjustably connected to said extension rearwardly of said body; arotatable knob engaging said abutment member rearwardly of said body; apair of actuator rods slidably mounted in said body to opposite sides ofand generally parallel to said stem and extending to the rear of saidbody; said knob including oppositely extending eccentric portionsrotatable into and out of alinement with said rods to accommodate andprevent, respectively, rearward movement of said knob by said rods;detent means between said knob and said rods normally retaining theeccentric portions of said knob in alinement with said rods anddeterring re-alinement of the same when they are not in alinement; andmeans for moving said rods.

10. In a spray gun having a body and a nozzle detachably secured to thefront end of the body, a valve seat member mounted in the body at thefront end thereof, said member having a conical bore extendingsubstantially entirely therethrough and defining a valve port ofpractically no axial extent at substantially the plane of the front endof said member and a conical seating surface rearwardly of said port,and a generally spherical valve member yieldably biased against saidseating surface and retractable from said surface and out of said portfor causing liquid to follow the contour of said seating surface andemanate from said port as a spray when the nozzle is detached from thebody.

11. In a spray gun as set forth in claim 10, said valve membercomprising a valve ball of a diameter only slightly greater than saidport and projecting into at least substantially the plane of said port.

12. In a spray gun as set forth in claim 11, stem means on said valveball including a exible portion accommodating movement of said ballrelative to said seating surface.

References Cited UNITED STATES PATENTS 1,249,090 12/1917 Hoff 251-333 X1,675,979 7/1928 Laird.

1,941,134 12/1933 Dodge 251-89 2,579,567 12/1951 Greene 251-155 X2,694,410 11/1954 Ey 251-356 X 2,942,791 6/1960 Bush et al. 239-526 X3,000,576 9/1961 Levey et al. 239-526 X 3,077,896 2/1963 Weingard251-333 X 3,116,020 12/1963 Rosen `et al. 251-294 X 3,190,564 6/1965Liedberg 251-294 X M. CARY NELSON, Primary Examiner.

R. C. MILLER, Assistant Examiner.

